Progress 10/01/05 to 09/30/06
Outputs
Progress Report 4d Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and Ohio State University (OSU). Additional details of research can be found in the report for the parent CRIS 3620-22410-007-00D entitled "Microbial Production and Formulation Technologies for Biocontrol of Fungal Plant Diseases" under the additional accomplishment entitled, "Field confirmation of reduction of Fusarium head blight using effective combinations of diverse biocontrol agents and a moderately resistant wheat cultivar." Collaborative research conducted in the past year was based on the premise that the integration of diverse control measures is widely considered to offer the greatest opportunity for limiting the impact of Fusarium head blight (FHB) which necessitated the development of new biological control techniques and strains to enhance the great potential of biocontrol for contributing to the integrated control of
FHB. In previous research, we have demonstrated the potential of several antagonists including the yeast Cryptococcus nodaensis nomen nudum OH 182. 9 (NRRL Y-30216) to significantly reduce the severity of FHB in field environments when biomass was produced in laboratory and pilot-scale quantities in liquid culture. Combinations of biological control strains potentially increase the efficacy and consistency of biocontrol. The objective of our study was to determine if combinations of strain OH 182. 9 and choline metabolizing antagonist strains (microorganisms capable of utilizing choline; a compound implicated in stimulating early growth of the fungal causal agent of FHB) would enhance biocontrol compared to levels obtained with individual strains. We demonstrated that combining choline metabolizing strains (CMS) with strain OH 182.9 frequently reduced FHB disease severity compared to the untreated control in greenhouse tests on spring wheat and field tests on Freedom wheat in
Wooster, Ohio, though reductions were only marginally greater than that obtained with strain OH 182.9 used alone. The best disease control (40% reduction in severity compared to the untreated control) was obtained by combining the use of the moderately resistant cultivar Freedom with antagonist combination treatments such as yeast OH 182.9 and Pseudomonas sp. AS 64.4 or OH 182.9 combined with all three CMS. A similar level of control was obtained using Folicur 3.6F. The fungicide and microbial treatments only occasionally reduced (and sometimes increased) FHB on the susceptible cultivar Elkhart. Our results offer proof of the success and necessity of utilizing and strengthening all available tools in the integrated management of FHB. Production, agricultural, and scientific communities have additional evidence of their obligation to promote collaborative research on improving and integrating all available tools for reducing FHB.
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Progress 09/13/01 to 09/12/06
Outputs
Progress Report Objectives (from AD-416) Optimize the production and deployment of organisms for biological control of wheat scab. Approach (from AD-416) Optimize biocontrol of wheat scab incited by Gibberella zeae (anamorph, Fusarium graminearum) as follows. Using greenhouse and field plant bioassays, evaluate the effects on biocontrol efficacy of multiplexing applications of superior biocontrol agents of scab of wheat that were discovered in previous cooperative research between ARS and The Ohio State University. Determine the feasibility of combining biocontrol agents with top fungicides and most resistant cultivars to acquire additive or synergistic levels of scab disease control. Improve bioreactor liquid culture media and incubation conditions to increase the quantity, efficacy, amenability to formulation and shelf-life of biocontrol agent biomass produced. Through the use of molecular and bioassay techniques, determine the disease reduction mode of action of a biocontrol agent that is superior in reducing wheat scab. Significant Activities that Support Special Target Populations This report documents research conducted under Specific Cooperative Agreement 3620-22410-007-02S between Agricultural Research Services and Ohio State University (OSU). Additional details of research can be found in the parent project 3620-22410-007-00D entitled "Microbial Production and Formulation Technologies for Biocontrol of Fungal Plant Diseases." As a result of our collaborative research effort, the capability of the food grade dye napthol yellow to protect microbial inoculants from the deleterious effects of ultraviolet (UV) exposure was identified for the first time in vitro. We demonstrated that the integration of biocontrol agents Cryptococcus flavescens Ohio (OH) 182.9 and Arthrobacter sp. OH 221.3, Folicur 3.6F, systematic acquired resistance (SAR) chemical salicylic acid, and UV protectant napthol yellow using a fractional factorial field design had mixed results that varied with the wheat cultivar tested. On cultivar Elkhart in Wooster, OH, the presence of fungicide Folicur 3.6F and antagonist OH 221.3 significantly reduced disease severity and incidence. Antagonist OH 182.9 reduced the deoxynivalenol content and naphthol yellow decreased the test weight of Elkhart grain. Treatments rarely had an effect on Fusarium head blight (FHB) symptom expression on moderately resistant cultivar Freedom. Analysis of data did not indicate the presence of first-order synergistic effects of combining the biocontrol agents, UV protectant, Folicur 3.6F and SAR chemical. Our discovery and demonstration that a food grade dye can protect biocontrol cells from the deleterious effects of UV light while showing no toxic effect to cell growth in the absence of UV will promote further consideration of a new group of compounds for use as UV protectants of biological materials that are employed in environments where degradation via UV light occurs. Food grade dyes can be included in formulations of biocontrol agents with little possibility of having a deleterious impact on product viability or, ultimately, the registration of the product. The difficulty in clearly interpreting results of using a fractional factorial design to evaluate multiple field treatments for the integrated control of FHB gives researchers additional information to evaluate in considering whether to use this powerful tool for evaluating multiple treatment effects in a decidedly variable field environment. Additional experiments using partial factorial designs in FHB field studies would be necessary to determine if this design can serve as a useful tool for researchers looking to maximize the number of treatments evaluated while minimizing the amount of field area required for the test. Monitoring activities took place within this project in the form of telephone calls and emails on at least a monthly basis. Personal visits with the collaborator took place two times during the period covered in this report when field trials were established and later monitored at the Wooster field facilities of the collaborator.
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Progress 10/01/04 to 09/30/05
Outputs
4d Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and Ohio State University (OSU). Additional details of research can be found in the report for the parent CRIS 3620-22410-007, "Microbial Production and Formulation Technologies for Biocontrol of Fungal Plant Diseases" under the additional accomplishment entitled, "Demonstration of the utility of chemical inducers of systemic acquired resistance (SAR) for reducing Fusarium head blight (FHB) of wheat when used alone or in combination with biocontrol agent Cryptococcus nodaensis OH 182.9." Through February of 2005, this collaboration consisted, in part, of a visiting postdoctoral OSU scientist being stationed in Peoria, IL, to assist in optimizing the production and deployment of microorganisms for biological control of Fusarium head blight of wheat. This discovery demonstrated that chemical SAR inducers can induce resistance in wheat against FHB,
and that improved control of FHB disease can be achieved by incorporating chemical inducers of SAR with the FHB biocontrol agent OH 182.9 under greenhouse conditions. Field trials to test combinations of biocontrol agents active against FHB were conducted at the OSU Wooster field station as part of research conducted under this SCA.
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Progress 10/01/03 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report This report serves to document research conducted under Specific Cooperative Agreement between ARS and The Ohio State University (OSU) which enables collaborative effort in completing the objectives of the parent CRIS 3620-22410-007, "Microbial Production and Formulation Technologies for Biocontrol of Fungal Plant Diseases." Additional details of the research can be found in the parent CRIS. This collaboration consists, in part, of a visiting postdoctoral OSU scientist being stationed in Peoria, IL, to assist in optimizing the production and deployment of microorganisms for biological control of Fusarium head blight of wheat. Through this SCA, field testing of experimental formulations of biomass from new production protocols is also made possible and an essential step in biocontrol product development is addressed. A major accomplishment from this SCA during the past year is
described in the AD-421 for the parent CRIS in section 4A, under the subheading "Discovery that cold shocking proven Fusarium head blight biocontrol agent Cryptococcus nodaensis OH 182.9 during inoculum production improves cell survival of drying stress." This discovery provides methodology to produce a more effective, air-drying-tolerant biocontrol cells thereby enhancing the possibility of producing a commercially available FHB biocontrol product using this patented strain.
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